Grading of Module 3 Assignment: Exploring Australia’s coral reefs. My finished plots match perfectly with expected plots. I have submitted my work for grading many times, using the exact same file submitted. The grader scores my work at random, as 20, 40, 60, or 80 %, but never 100%. Ex4 claims “hist_ax2 does not appear to be a histogram.” Obviously it is correctly shown, both in the coding and in the plot. Also the grader reports: “Unexpected error” and “Unable to find object required for grading in your code” at randomly selected Ex1 through Ex5. I started with a new notebook, and surgically inserted the necessary replacements for None everywhere. I followed all instructions. Please have a human contact me about having them grade my work.
Hi there, I’m a human contributor to Jupyter, the open source project! 
started with a new notebook
Without knowing… anything about this, other than some names: depending on how the notebook was built, you may need to start with a copy of the original assignment notebook, as there may be metadata in particular cells (or the notebook itself), or use of unique cell_id that identifies it. Copy-and-pasting won’t always bring these things along.
Unfortunately, I have no further idea what this is talking about. You may want to seek a more appropriate help channel, such as your teaching assistant, professor, sensei or some email address provided by your learning platform.
Have a nice day!
Hi, Nicholas:
After solving the complete 5-step exercise, and could not get a consistent grade, I learned how to get a copy of the original assignment notebook and start over.I got that copy and carefully only changed the None text to the desired text. When I ran that new filled-in notebook,it ran without error.So I submitted it for grading. I submitted it many times, within an hour or so. The grade and the grading errors varied as stated.I am hoping that Coursera would be interested in fixing this grader problem. Attached is my solution to Coursera :Module 3 Assignment: Exploring Australia’s coral reefs. I think I deserve a 100% from Coursera. Unfortunately, I do not know how to reach the authors of this course. I will try to find them next.
Arne
(Attachment C3M3_Assignment.ipynb.txt is missing)
hoping that Coursera would be interested in fixing this
Me too!
I sent Sean Barnes a request to identify who/where I can get help from Coursera. I did not hear from him this morning, but I ran every step again and this time an error in a name was detected that had never been found before. I updated the name, ran all again, and submitted for grading. It now found my grade to be 100%! Someone quietly fixed the grader. Problem solved!